Proximal attachment of long head of biceps brachii to the bicipital tubercle of scapula and its functional significance

Introduction

Lesions affecting the tendon of Long Head of Biceps brachii (LHB) are among the more frequent causes of pain and disability in the region of shoulder joint. Shoulder arthroscopy has shown that there is dual attachment of LHB to the Supraglenoid tubercle (SGT) and glenoid labrum, but the origin from the bony prominence on upper part of dorsal surface of neck of scapula has not been described in the literature reviewed. This bony elevation has been named as “Bicipital Tubercle (BT)”. What is astonishing is the fact that such a prominent BT has been either missed or ignored by earlier workers.

Methods

During the dissection of the shoulder joint, the tendon of LHB could be separated into superficial and deeper laminae. The fibres of the superficial lamina could be traced to BT in approximately 80% cases.

Results

In 70% of specimens LHB was seen to join the posterior labrum; in 20% the anterior labrum and in the remaining to both the labrum. In 57% of right and 65% of the left scapulae the BT was very prominent

Conclusion

The efficiency of action of LHB is enhanced by its getting a firm attachment to the bicipital tubercle (BT). Thus in man the origin of the tendon of LHB has shifted from only the SGT to SGT plus labrum, and further has got an additional attachment to BT. This attachment to the BT seems to have been overlooked and demands its inclusion in all the future studies.